Japan's Nocturnal Farming Shift: A Data-Driven Response to Lethal Heatwaves

As extreme heat reshapes Japan's agricultural calendar, a growing cohort of farmers is abandoning traditional daytime routines for nocturnal operations. The shift, driven by record temperatures and a vulnerable ageing workforce, offers a case study in climate adaptation with significant implications for regional food security and labour productivity across ASEAN.

Why Japanese farmers are moving to nighttime work

The economic calculus is stark. In 2024, heat exposure cost Japan's agricultural sector 926 million labour hours, according to Lancet Countdown. Across all sectors, lost labour hours nearly doubled from the 1990s average, translating to roughly US$46 billion in forgone income, or about 1 per cent of Japan's GDP. For a nation where approximately 70 per cent of farmers are aged 65 or older, the risk profile is particularly acute.

Motoaki Iijima, 36, owner of the Nikko Engei flower farm north of Tokyo, converted his family's rice farm a decade ago. Three years ago, after a part-time worker suffered heatstroke, he shifted operations entirely. Outside temperatures above 35°C, increasingly common in his region, can push greenhouse interiors above 40°C. Now, Iijima works outdoors through the night, stopping only when the morning sun becomes punishing.

“The hours around dusk are really precious. That's when we can be outside. We've gradually become nocturnal. It's about protecting our bodies, and ultimately, our lives.”

Heat-related fatalities among agricultural workers are rising sharply

The human toll is measurable. A record 59 agricultural workers died from extreme heat in Japan in 2024, more than double the 2021 figure. A 2025 Japan Weather Association survey found that about 60 per cent of farmers in their 20s to 50s had either personally suffered heatstroke or knew someone who had. Nearly 60 per cent of farmers have shifted their working hours to earlier or later in the day.

On Iijima's farm, veteran worker Miyoko Asada, 68, arrives shortly after sunrise. “We've got to race against the clock,” she says, hurrying to cut purple asters before temperatures climb past safety limits.

Poultry farmers face a parallel crisis in livestock management

Tetsuya Usuba, 48, a poultry farmer a few towns away, lost over 500 laying hens to heatstroke six years ago during a three-day heat spell. His midnight routine is now fixed: lights automatically flick on in two barns at 2.30am, waking the 4,400 caged hens to eat before oppressive heat suppresses their appetite. He has installed additional fans, sprays water on metal roofs, and adds citric acid to drinking water. Still, when temperatures spiked above 35°C in July, he lost 130 birds.

“Summer has become a new threat to producers like us, something as scary as an outbreak of avian influenza.”

Policy response: new workplace regulations and smart farming incentives

The Japanese government has responded with regulatory and technological measures. New workplace regulations introduced in 2025 require employers to establish heatstroke reporting procedures and emergency response plans. Tokyo is also promoting smart farming technologies, including drones and robots, to reduce workers' heat exposure.

For ASEAN economies watching closely, Japan's experience underscores the intersection of climate risk, demographic vulnerability, and agricultural productivity. The region's own agricultural sectors, similarly exposed to heat stress, may find Japan's adaptive playbook instructive as they navigate their own climate trajectories.

What does this mean for regional agricultural policy?

Japan's nocturnal farming experiment offers three takeaways for regional policymakers. First, data-driven risk assessment is essential: quantifying labour hour losses enables targeted interventions. Second, demographic vulnerability requires tailored solutions, particularly for ageing workforces. Third, a hybrid approach combining regulation, technology adoption, and manual adaptation can yield results, even under extreme conditions.

As Iijima pauses and glances at the overcast sky, the pattern is clear: before long, the heat will return. The question for Japan, and increasingly for Southeast Asia, is how quickly adaptive measures can scale.

Frequently asked questions about Japan's nocturnal farming trend

How many Japanese farmers have died from heatstroke?

A record 59 agricultural workers died from extreme heat in Japan in 2024, more than double the death toll in 2021.

What is the economic cost of heat exposure in Japan?

Heat exposure cost Japan's agricultural sector 926 million labour hours in 2024. Across all sectors, lost labour hours translated to roughly US$46 billion in lost income, about 1 per cent of Japan's GDP.

What government measures has Japan introduced?

Japan introduced workplace regulations in 2025 requiring heatstroke reporting procedures and emergency response plans, alongside promoting smart farming technologies like drones and robots.